My first boat

Not totally of course, because you have trim adjustment. Manufacturers normally assume an angle on the stern that fits within their trim range for big motors, and an optimal angle for smaller motors without automatic trim.

If you trim your outboard with a vertical stern, you may find that the maximum down trim is insufficient. That is, maximum downward (or forward) trim wont be enough to get an angle to push the stern up for some operations.

In any case, if your motor is operated on a totally vertical axis, you don't get the 'planing' on cornering, as per the very small motors.


edit


here's a thread where the guy built a vertical transom, and had to insert wedges because his motor wouldn't trim down enough

http://forum.woodenboat.com/showthread.php?120308-Outboard-Motor-Transom-Angle

 

Which gets back to my early statement that since at least the 30's transoms have been built to aproximately 14 degrees. I don't know why. However, any standard angle would work as long as they are all in agreement.

 

I missed your post as I put my edit in.

Most modern outboards rely on a sloped transom, to get that angled drive

the link at

http://forum.woodenboat.com/showthread.php?120308-Outboard-Motor-Transom-Angle

is a classic example.

If the angle of the prop to the turn axis isn't correct ( around 12 d), the hull turn angle will be flat.

 

This is my first boat build. I was so close to buying a cheap 250 dollar one. Till I got a 4hp 2 stroke outboard for $50 so I built one. I wanted a beautiful skiff but I wasn't experienced yet. So instead of messing up a stitch and glue and spend booko money. I just built me a 12' jon boat with a flipping deck. Took it in the lake and it goes over logs like nothing. It only goes 2 inches deep with 700lbs in it !damn!. Its 38 inches wide at the widest and 32 at the narrowest. Its no tipsy at all. The back is tilted a lil over 14 degrees I think it was 21 degrees. I had to have a raised transom since it was a long shaft. I used 11/32 ply and its sturdy. I used 2 of 3/4 red oak on the transom cost me a pretty penny. I used 2x2 chine logs. 2x1 for runners. Used 12x1 to re-enforce the joining ply. No joy should of used steal or 2x6. Wife dropped the boat of the bed of the truck and crack the 12x1's. I just got roofing steal plates and screwed them in. Now the boat is amazing. I took her into the bay during rough waters in storm. I have a pic of the boat taking on water lol. Water was coming over the bow and soaking us lol. It was a hassle to build but I love the looks I get when I am in it. People stare and think dumb rednecks...... She is light about enough I load her myself when dry. After being in the water she gets a bit heavy that I need two people. I got handles on it. All joints are spaced so if she swells she wont pop out of place. The paint is made to take in small amount of water and breath with anti fouling. This way the wood wont dry rot or just rot in general. I don't leave her moored so I just used a general oil based paint. With engine, boat, anchor, paddle, and paint I spent $300.

http://images.craigslist.org/00c0c_8Xhug9VHOWz_600x450.jpg

 

She'll do the job!

 

Don't know how I missed this... I always love talking about my stuff! Chugger can be the biggest little boat if you do it up right. One of them (now past it's prime and sprouting mushrooms ) used to travel down the Mississippi from Minneapolis to Lake Pepin (about 70 miles) yearly to the messabout there. There are/were probably 10 or so in existence at one point in time... don't know about now though.

 

No, it's to do with hydrodynamic forces against the deadrise of the hull during a turn. Deep V hulls bank inwards a lot. Flat bottom boats like punts don't bank inwards at all, and if anything tend to bank slightly to the outside due to the lateral resistance of the vertical sides (as well as just generally being rather scary and nasty around corners).